Striking-tool.



25 ready todeliver a blow; ig.

; 4o 7 able form of tool, herein, by way ITE STATES PATENT onmcn.

WILLIAM-;' 0. MICHAEL, or CLAREMONT, 'NEVJ HAMPSHIRE.

' sTnIKms-Toon To all whom it. may-concern:

. .fBe it known that"If,'\VI LL1A t C. MICHAEL,

State of New Hampshire. Improvement in Striking a citizenof the United Statesfresiding at Claremont, in the county;

olsfof whieh the connection with the following description, in

a specification,

accompanying drawings, is

- like numerals on the drawings representing like parts.

- This invention relates to striking tools,

being more particularly concerned with the provision of improved means for. adjusting the stroke of striking tools, such, for example, as center-punches, dental pluggers, or

other tools of this description.

best understood by My invention will be reference to the following description when ."takenin" connection with the accompanying of,while its scope will be more pointed out in the appended claims.

illustration of one specific embodiment there- In the drawings: Figure 1 is a. central,

1 sectional elevation showing-a tool embodying 8 located within a chamber in the tip and abutting, one end against-a collar or enlargement on the punch rod, "the guide member 5.

' punch rod section showing.

therein disclosed, which one form of my invention 2 is a similar the parts in normal 'position; Fig.3 is a planview, in section, taken on the line 3-3, Fig. 2; and Figs. 4, 5, 6 and '71 aresimilar sections in plan taken on the ,lines 4e 4=;' 5%); 6-7-6; 7 7, in Fig. 2.

respectively,

'Referring to the drawings and to thetool I-have selected for illustrating the principles of my invention, the same comprises a holder 1, herein consisting of 'a hollow cylindrical shell or tubu s lar casing, having the tubuhti"'t-ipor nose piece 2 through which projects the punch v rod'3, the latter carrying at'its end any suit of example, a simple center punch.

The punch rod has a sliding fit through. the tip 2 and is normally projected to the position in Fig. 2 by means of the coiled spring and the other against The latter forms a second guide or hearing through which the slides and, like the nose piece, is

threaded into thehead end ofthe tubular casing 1, being provided'witlrthe holes 13 to particularly with the parts just Specification of Letter-s Patent.

ofv Sullivan and lve'finvented'an Patented Jan. 25, 191131.

Application filed April 2, 1909. Serial No. 487,552.

facilitate screwing it into or unscrewing-it from the casing.

The to'tl is operated by applying the-end of the punchrod to the work and depressing the holder againstthespring 8,} devices be;

ing provided within the casing-' .wherebv hammer blow is delivered to the end of the ptu1ch -.-rod, ,which hannneigfblowis herein made-adjustable both'as to ,the force and the length-oi stroke of the hammer member.

To deliver the hammer blow the holder has within: it the hammer member -t, which isadapted reciprocativelyto slide within the casing, there being interposed between the rear of the hammer member and the Y closed end of the casing the hammer spring strike the desired blow but the han mer member moves with it until it is caught and held against furtherdepression at a predetermined distance from'the' punch rod by suitable holding means, whereupon further depression-of the holdenresults in compression of the hammer spring.

Subsequent depression of the holder finally causes the holding means mer, permitting the compressed. hammer spring to ,drive itseat 27 of the bore 30 to deliver the hammer against t-he upper end ot' the punch rod.

wane devices maybe emplqved, herein I have showna looking or holding pawlt), pivotall} mounted upon the slot or opening in the punch rod the bottom any"suitable holding and releasing pin 10,. within the narrow I to release the hamdown-wand and cause the and top of the slot being designated by 24 and 25 respectively. This pawl is adapted to catch but subsequently described.

end of the pawl26 is normally pressed ou'tward by the spring 9 and slides in one of several longitudinal grooves being shownby way of example, in the groove 19, which is of substantially semi-circular cross-section (as to release the hammermemher on depression of the holder, as

- .ioo' As-herei'n shown, the upper or holding are provided four such grooves 19, 20, 21 and 22, spaced at equal distances about the said bore, but a greater or lesser number may be employed, desired, and the shape and arrangementv of such grooves may be other-- wise widely varied, and formations other than a grove formation may be employed.

When the holder is depressed from the position shown in Fig. 2 toward that shown in Fig. 1', the hammer member 4 descends with the holder with the projecting end 26 of the pawl resting in .the groove 19. At a suitably selected pointin the groove there is provided'a depression or opening 15 presenting a shoulder into which depression the pawl-end 26 is forced by the spring 9 as soon as it comes into registration therewith, moving the pawl to the position shown in Fig. 1.

The hammer member is then held fast against further depression of the holder,

' which merely causes the compressionof the two springs 7 and 8.

The lower end of the pawl is provided with a releasing projection 29 which normally lies within the slot formed in the punch rod, but which, on' the holding movement of the pawl described, is swung out to,

project beyond the surface limits of the punch rod. As the depression of the holder continues such releasing projection is engaged by the lower end of the guide member 5 which swings the pawl inward, withdraws the holding end-26 from the depression 15 and thereby releases the hammer member, which is instantly thrown down by the hammer spring'to'deliver its blow. When downward pressure is relieved on the casing or holder'the spring 8 expands and lifts the same again to the position shown in Fig. 2.

i It will be seen that the position of the de-' pression shoulder 15 governs both the length of the hammer stroke and the compresslon of the spring. If the shoulder is located farther to the rear than is the shoulder 15 the holding ofthe hammer, which occurs when the holderis depressed, is delayed so much the longer, and thelength of the blow 2'. c. the distance between the top of the punch rod and the bottom 27 of the bore 30. when the hammer is thus caught, is correspondingly shortened and the extent of com" pression of the hammer spring correspondingly reduced, so that, the stroke is lighter and shorter.

' Means are herein provided whereby the particular point in the depression, at which the hammer is arrested and compression of the spring begins, may be varied,-and herein this is accomplished by adjustable parts requiring no additional exterior or visible members.

changing mechanism maybe secured locking the pawl, or other holding member '20, 21 and 22 are provided, the said grooves having their respective depressions or shoulders'15, 18, 17 and 16 located at ditl'erent positions lengthwise the hammer bore. To permit the pawl to be operatively related to any one of the several grooves at will, the lower portion of the bore 30 is counterbored or enlarged at 14 (see Fig. 6) so that the grooves have their transverse depth dimin-.

i'shed by the counterbore and are relatively .shallow. iVhile, therefore, the pawl, when resting in the lower, shallow portion of any one of the grooves, is suitably and sufiiciently guided to be maintained therein against accidental displacement, it is not positively held therein as in the deeper portion of the groove, but, by turning'the pro jecting portion of thepunch rod in the holder, when in the position shown in Fig.

2-, the holding end of the pawl can be readily I snapped from one groove to another at will.

.Preferably, though not necessarily, the hold-- ing pockets for the several grooves taken in rotation are located at distances which in crease by equal steps from the forward end of the tool so that, by turning the punch rod when in its normal position, the operator can gradually increase the length of the hammer stroke from a minimum to a maximum, or vice versa, by equal steps.

Since the length of the working stroke of the hammer and the amount of compression of the hammer spring increases or decreases simultaneously and by equal amounts, a

greater range in the intensity of the blow is obtained than has been possible with other tools of this class where the only adjustment provided has been in changing the compression of the hammer spring. i

It is to be understood that the strolieelsewhere than upon the punch rod as, for example, upon the hammer, as well. as by providing other means for varying the stroke than separate grooves or the like, it being understood that I have herein illustrated but one specific embodiment of my invention. the details and form and relative arrangement of parts being susceptible of extensive changes without departing from the spirit of the invention.

Having thus described my invention, what I claim is:

1. In a striking tool, the combination with a punch member, of a hammer member, a casing or holder, a spring between the casing and the hammer'member, said casing being depressible about the punch member against said spring, holding means to arrest the depression of the hammer member releasing means to release the hammer member at a given point in the depression of the casing,

To this end the four grooves 19, l and means for varying the point in the desion of-the hammer member is arrested.

. a hammer member, of a punch member, a'

ldi g portions at will.

.- a hammer member, of a pundh member, a 'caslng or holder, a spring between the, cas- 1 depression of the hammer-member against the compression of. the spring, comprising ing member on subsequent depression of the havinga point of diminished depth 'whereat the holding member may be turned toeni g. J v1 mg for the wlthdrawal of the holdin member from'the holding shoulder on subsea holder, a hammer member, a punch memblowion the depression of the holdingmenr' her, and means governed by the rotation of .said tool having -a Ipluralityof holding 'por for varying bothfthe I means.

pression of the casing at which the depres- Y 2. In astriking tool, the combination with depr'essibleholder, a spring between the ho der and the hammer,-a' holding member,

tions arranged 'circumferentially at difier'ent points lengthwise the same for engaging'said holding member to arrest the depression of. the hammer, and 'releasingmeans for subsef' member being adapted, through the turning of the punch member relatively to the holder, to be operatively related to any one of said 3. In a striking tool, the combination with ing and the hammer member, said casing being depressible about the punch member against said spring, means for arresting the a movable locking memberon theone hand and a group of lock-receiving portions, one

upon the punch member and; the others uponv the hammer member, said locking member being adapted to be presented at will for" engagement with any of said lock-receiving portions, and meansgfor releasing the lock casing. I j 1 ,4. In a striking tool, the 'combinat-ion'with a hammer member, of" a punch member, a holder, a springbetween' the hammer member and the holder, said tool having a pivote'dholding member and a set of grooves arranged, one'uponthe punch member and the other upon the hammer member, said ent points lengthwise the tool, said grooves e with anyone at will, and'means pro quent depression of the holder. v

5. In-a striking tool, the combination-with ber, impellingmeans for causing the ham-.

m'er member -to strike the punch member a theholder relatively to the punchm'ember length of the blow and the impulse imparted by the lmpelllng.

; 6. In a striking tool, the combination with a holder, a hammer member, apunch memtering the tool end of the barrel for her, impelling means for causing the-ham- 'mer.member to strike'the punch membera blow on depression of the-holding member, and meansigoverned by, the rotation ofthe holder relatively to the punch member for varying at will the force of the impelling 7. In a striking toolthecombination with 'a casing 1, the punch member-3, the hammer member 4-, within the casing tor' imparting a blow to the punch member, an impelling spring 7 for the hammer member, and a conquently releasing 'the same, said holding:-

trolling pawl 6 for the hammer member, there being provided the grooves" 19,20, 21. and 22 within which the pawl; member is adapted to ork, and also holding recesses 15, 1.8, 17 and -16 for engagement withlthe .89

controlling 'pawl..

8. In a striking tool,'the' combination with f a'punch member, a hammer member, a depressible holder, a spring, an] adjustable j stroke changing mechanismcomprising a 85. pivoted catchcarried by one m'einber,:and a fplurality of longitudinal groovesformed-in another member, said'grooves having difie'n entiallyspaced shoulders for" engagement with the catch.

9. An automatic striking tool having a tubular casing closed at one end, a spring- "actuated striking rodgslidablyj mounted in saidcasing, a spring-actuated paWl-pivotally secured to'said striking rod, and a 951] spring-actuated hammer member slida-bly mounted nisald casing, said hammer mem' ber having a! plurality of longitudinal groov'es'presenting a plurality ofdifferen-j tially spaced shoulders and said rod being rotatable to. engage groove at will. r j

110. In a st riking.'to0l,-.the combination with a punch member, a hammer, member, a

saidlpawl' with any holder,-means ,for causing the hammer mem-f her to strike the punchmember on depres-. sion of the holder, and means governed by the rotation of the older relatively t punch member to vary the's'troke.

o the 1 1-1; In a strikingtool, the combination 1 10 with a punch member, of a hammer member, a holder, a releasing device for releasing the hammermember to strike the punch member on depressionfof the holder, and means govern'ed by/[he rotationof the holder rem-.115

tively tothe'punch member for varying the. point. in depression when said releasing device becomes effective. v.

-. 12. In a striking tool" the combination with a holder barrel, of a hammer member, 1201 impelling means and adjustable means enadjust-- ing the stroke ofthe hammer. I

13. In a striking tool the combinationwith .'a holder barrel, of a hammer member,

impelling means, and means adjustable through the tool end otv the barrel for adjusting the force of the impelli'ng means.

14. In a striking tool the combination name to this specification, in the presence of with fit holder barrel, (211 a hammerdmembke'lr; two subscribing witnesses. v 4 1 1m e in means .an means a 'usta e 4 thl ugh the end of the barrel for imrying I WILLIAM -M 5 both the length of the blow and the impulse Witnesses:

imparted by the impelling means. 7 CHESTER F. BRUCE,

In testimony whereof; I have signed my H. W. P. PUTNAM. 

